A method and an electronic circuit for regenerating an electrical contact are provided in order to remedy the problem of electrical contacts becoming highly resistive over time. electrical contacts become highly resistive over time, particularly when the contacts are thermally highly stressed and/or exposed to corrosive gases. To remedy this undesired effect and to reestablish the low resistance of the contacts, an electrical regenerating signal is applied to these contacts.
|
9. A method for regenerating at least one electrical contact of an electronic component, comprising:
monitoring an electrical impedance of the electrical contact;
generating and outputting a regenerating signal to the electrical contact; and
short circuiting at least one element within the electronic component.
5. An electronic circuit for regenerating at least one electrical contact of an electronic component, comprising:
a monitoring device for monitoring an electrical impedance of the electrical contact;
a signal generator for generating and outputting a regenerating signal to the electrical contact; and
a switching device for short circuiting at least one element within the electronic component.
1. An electronic circuit for regenerating at least one electrical contact, comprising:
a monitoring device for monitoring an electrical impedance of the electrical contact; and
a signal generator for providing a regenerating signal to the electrical contact in response to a first control signal output by the monitoring device if the electrical impedance of the electrical contact is highly resistive, wherein:
the signal generator generates a pulse sequence as the regenerating signal, and
the electrical contact is situated within an electronic component of the electronic circuit; and
a switching device for selectively short circuiting at least one element within the electronic component, except for the electrical contact, in response to a second control signal output by the monitoring device, if the impedance of the electrical contact has fallen below a specified resistance threshold.
2. The electronic circuit as recited in
3. The electronic circuit as recited in
4. The electronic circuit as recited in
6. The electronic circuit as recited in
7. The electronic circuit as recited in
8. The electronic circuit as recited in
the monitoring device includes a control device for detecting an internal resistance of the electronic component,
a detected high-resistance value for the internal resistance is interpreted as an indication that the electrical impedance is highly resistive, and
the signal generator includes a current source controlled by the control device, the control device outputting a sequence of current pulses to the electrical contact in response to a first control signal.
|
The present invention relates to a method and an electronic circuit for regenerating at least one electrical contact.
It is known from the related art that thermally highly stressed electrical contacts, particularly if they are additionally exposed to corrosive gases, are prone to oxidation or corrosion. The occurrence of oxidation or corrosion has the disadvantage that the affected electrical contacts lose their originally good conductivity and become highly resistive over time, which is undesirable. The same unwanted effect, for example, is also observed as a result of Braun deposits and/or other deposits on the contacts, or as a result of external inputs into the contacts during the production process.
In view of the above drawbacks, it is an object of the present invention to provide a method and an electronic circuit for regenerating a highly resistive electrical contact.
The above object is achieved by the present invention in that an electrical regenerating signal is applied to the contact if the impedance of the contact is highly resistive, or of low resistance. In the case where the impedance of the contact is highly resistive, the electrical regenerating signal has the advantageous effect of removing the corrosion and/or the deposit on the contact. Put more precisely, oxidation barrier layers, for example, produced by corrosive gases, or contaminants in the contact, which cause the high resistance of the contact, are removed by the electrical regenerating signal. The same applies to temporary blockages of electrode contacts, or deposits on the surfaces of a contact caused by external input, or by processing residues.
Even in the case where the impedance of the contact is of a low resistance, it may be advantageous to apply the regenerating signal to the contact, thereby achieving a preventive protection against the occurrence of high resistance.
The remedial effect of the electrical regenerating signal is especially effective when the regenerating signal takes the form of an electrical pulse sequence, in which case the regenerating signal may be referred to as “therapeutic pulses.” Exemplary embodiments of the pulse sequence are described below in further detail.
A further exemplary embodiment of the method according to the present invention provides for the electrical regenerating signal to act on the highly resistive contact not permanently, but only temporarily, that is, only at a defined point in time or during a predetermined temporal interval. Once the remedial effect of the regenerating signal has set in and the contact has been transformed from a highly resistive state back to a state of low resistance, the regenerating signal can be switched off. Alternatively, the regenerating signal may continue to be applied to the contact even after the onset of the low resistance state, thereby preventing a recurring emergence of high resistance of the contact in this manner.
The present invention also provides an electronic circuit for regenerating an electrical contact. According to the present invention, this electronic circuit includes a monitoring device for monitoring the electrical impedance of the electrical contact, and a signal generator for generating and outputting a regenerating signal to the electrical contact in response to a first control signal output by the monitoring device if the electrical impedance of the contact is highly resistive or of a low resistance.
Furthermore, for regenerating an electrical contact within a lambda probe, an advantageous exemplary embodiment of the electronic circuit according to the present invention utilizes a circuit for measuring the internal resistance of the lambda probe. In contrast to the related art, however, this circuit according to the present invention may be operated only when the contact to be regenerated within the lambda probe is highly resistive.
According to the present invention, the value of this resistance RK is monitored with the aid of a monitoring device 10. If this monitoring device 10 detects that the value of the resistance RK of the electrical contact exceeds a specified first resistance threshold value, because, for example, in an undesired manner the contact became highly resistive due to contaminants introduced, then monitoring device 10 produces a first control signal S1 for triggering a signal generator 20 of the electronic circuit.
In
A regenerating signal IReg of this form has the advantageous effect that the blockages or insulating layers within the contact that cause the high resistance are removed, and hence the contact regains its low resistance. As soon as the contact has regained its low resistance, the regenerating signal can be switched off. To this extent, the regenerating signal need only be applied temporarily to the contact.
In
To prevent this, monitoring device 10 is further designed to generate a second control signal S2 and to output this, for example, to a second switching device 50. In response to second control signal 52, if the value of resistance RK of the contact has fallen below a specified second resistance threshold value, switching device 50 short-circuits at least individual elements of electronic component 30 (except for the contact itself), and/or additional electronic components of the circuit. This short-circuiting to ground achieves the result that regenerating signal IReg is not discharged via the short-circuited elements or components, but via the short circuit to ground, thus preventing the regenerating signal from possibly destroying these elements of component 30. As an alternative to such a protective measure, in individual cases it may be sufficient to limit the amplitude of the regenerating signal from the outset to be so small that the regenerating signal would not destroy the affected individual elements or components of the circuit. Even a regenerating signal weakened in this manner can bring about the desired remedial effect in the electrical contact.
Generally, the regenerating signal may be fed to the contact to be regenerated via supply lines, as well as via signal lines within the electronic circuit.
The electronic circuit shown in
The inference typically drawn from this signal to the lambda value measured by lambda probe 30 of, e.g., the exhaust gas of an internal combustion engine rests on the basic principle that the temperature in the exhaust gas of the internal combustion engine can be assessed as the measure for the current air/fuel ratio at which the internal combustion engine is currently operated. Lambda probe 30 therefore contains the temperature-dependent resistance RT so as to be able to evaluate the voltage drop across this temperature-dependent resistance RT as the measure for the current lambda value. An operating point of this lambda probe is individually set with the aid of a heater (not shown) of the lambda probe.
A derivation of the correct lambda value based on the voltage drop across the lambda probe is possible only if the heater of the lambda probe is functioning properly and the internal resistance of the lambda probe is correctly ascertainable. Fundamentally, this internal resistance corresponds to the already mentioned temperature-dependent resistance RT. This is particularly relevant when the resistance RK of the electronic contact in lambda probe 30 is negligibly small.
To check the proper functioning of the probe heater and hence also the proper functioning of the lambda probe, control unit 10′ occasionally performs a measurement of the internal resistance RI of lambda probe 30. To this end, control unit 10′ activates the signal generator (or current source) 20 by issuing a first control signal S1. In this manner, a regenerating signal is given in the form of a regenerating current IReg, e.g., in the form of a sequence of current pulses across the internal resistance RI of lambda probe 30. Because the regenerating signal as well as the internal resistance of lambda probe 30 are known, if the lambda probe is intact, it must experience a predictable voltage drop. The actual voltage drop is fed to control unit 10′ via its input E in order to be subsequently compared to the expected voltage value. If the agreement is sufficiently high, it can be assumed that the lambda probe and particularly its heater are working error-free. This inference is particularly reliable if the internal resistance RI is low and the probe is warm or hot.
As can be seen in
A regeneration of the electrical contact within the lambda probe, however, is only necessary if the resistance of this electronic contact RK is high.
In the electronic circuit shown in
According to the present invention, therefore, the regenerating signal IReg produced by current source (signal generator) 20 is, for regenerating purposes, output to lambda probe 30, and particularly to its electrical contact, only when the lambda probe is cold or is not yet at operating temperature, i.e., when its internal resistance RI (as representative of the resistance of the electronic contact) is highly resistive.
This assumes that the detected high resistance level of the internal resistance is not solely due to the high resistance of the temperature-dependent resistance RT, but also due to an undesired high resistance of the resistance RK of the electrical contact, which, according to the substitute circuit diagram, is connected in series to RT. Only then is the functionality of the contact indeed significantly impaired, and only then does the contact require regeneration or a remedial measure through the regenerating signal.
Even in the alternative case, i.e., when the high resistance of the internal resistance RI results primarily from the high resistance of the temperature-dependent resistance RT alone and the resistance of the electrical contact is low, the application of the regenerating signal to the electrical contact is fundamentally harmless. This is particularly true as long as the regenerating signal is not excessively strong (e.g., in terms of amplitude) so as electrically to overload the other electronic elements within the lambda probe. But even in those cases where the contact has a low resistance, e.g., particularly when the lambda probe is at operating temperature, that is to say, during the operation of the internal combustion engine or shortly after it has been switched off, an application of the regenerating signal to the contact can be advantageous in order to prevent the contact from becoming highly resistive.
As an example, the regenerating signal may be applied to the electrical contact only during times when the useful signal, e.g., in the case of the lambda probe the λ measuring signal, is suppressed.
Schnaibel, Eberhard, Raff, Lothar, Maurer, Helmut, Hoerrmann, Oliver
Patent | Priority | Assignee | Title |
10416071, | Jun 04 2015 | Fanuc Corporation | Corrosion detection circuit for circuit board and motor drive having the same |
11562863, | Sep 11 2019 | Arc Suppression Technologies | Power contact electrode surface plasma therapy |
7362011, | Apr 05 2004 | Fujitsu Ten Limited | Apparatus for preventing corrosion of contact |
7486088, | Mar 30 2005 | Fujitsu Ten Limited | Method for preventing corrosion of contact and apparatus for preventing corrosion of contact |
7550878, | Apr 05 2004 | Fujitsu Ten Limited | Circuit for preventing corrosion of contact |
8337684, | Sep 30 2008 | Robert Bosch GmbH | Method for operating an exhaust gas sensor and device for carrying out the method |
9583403, | Jun 25 2015 | International Business Machines Corporation | Implementing resistance defect performance mitigation using test signature directed self heating and increased voltage |
9721856, | Jun 25 2015 | International Business Machines Corporation | Implementing resistance defect performance mitigation using test signature directed self heating and increased voltage |
Patent | Priority | Assignee | Title |
3417323, | |||
3794850, | |||
3996514, | Nov 21 1975 | Bell Telephone Laboratories, Incorporated | Circuit board contact resistance probe |
4173735, | Apr 19 1978 | Contact fault detector | |
4178543, | Feb 23 1978 | Teradyne, Inc. | Analyzing electrical circuit boards |
4491797, | Jun 01 1982 | Northern Telecom Limited | Test contact resistance of dry circuit contacts |
5091698, | Feb 04 1989 | Robert Bosch GmbH | Circuit for measuring the internal resistance of a lambda probe |
5258654, | Mar 30 1992 | Ranco Incorporated of Delaware | Computer-checking of the position of a switch whose contacts where oxidized |
20040130331, |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Jul 09 2004 | Robert Bosch GmbH | (assignment on the face of the patent) | / | |||
Aug 16 2004 | SCHNAIBEL, EBERHARD | Robert Bosch GmbH | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 015906 | /0713 | |
Aug 23 2004 | MAURER, HELMUT | Robert Bosch GmbH | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 015906 | /0713 | |
Aug 23 2004 | RAFF, LOTHAR | Robert Bosch GmbH | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 015906 | /0713 | |
Sep 10 2004 | HOERRMANN, OLIVER | Robert Bosch GmbH | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 015906 | /0713 |
Date | Maintenance Fee Events |
Mar 11 2010 | M1551: Payment of Maintenance Fee, 4th Year, Large Entity. |
Mar 13 2014 | M1552: Payment of Maintenance Fee, 8th Year, Large Entity. |
Apr 30 2018 | REM: Maintenance Fee Reminder Mailed. |
Oct 22 2018 | EXP: Patent Expired for Failure to Pay Maintenance Fees. |
Date | Maintenance Schedule |
Sep 19 2009 | 4 years fee payment window open |
Mar 19 2010 | 6 months grace period start (w surcharge) |
Sep 19 2010 | patent expiry (for year 4) |
Sep 19 2012 | 2 years to revive unintentionally abandoned end. (for year 4) |
Sep 19 2013 | 8 years fee payment window open |
Mar 19 2014 | 6 months grace period start (w surcharge) |
Sep 19 2014 | patent expiry (for year 8) |
Sep 19 2016 | 2 years to revive unintentionally abandoned end. (for year 8) |
Sep 19 2017 | 12 years fee payment window open |
Mar 19 2018 | 6 months grace period start (w surcharge) |
Sep 19 2018 | patent expiry (for year 12) |
Sep 19 2020 | 2 years to revive unintentionally abandoned end. (for year 12) |